Rana Cyanophlyctis Research Articles

Genetic divergence and evolutionary relationships in six species of genera Hoplobatrachus and Euphlyctis (Amphibia: Anura) from Bangladesh and other Asian countries revealed by mitochondrial gene sequences

To elucidate the species composition, genetic divergence, evolutionary relationships, and divergence time of Hoplobatrachus and Euphlyctis frogs (subfamily Dicroglossinae, family Ranidae) in Bangladesh and other Asian countries, we analyzed the mitochondrial Cyt b, 12S, and 16S rRNA genes of 252 specimens. Our phylogenetic analyses showed 13 major clades corresponding to several cryptic species as well as to nominal species in the two genera. The results suggested monophyly of Asian Hoplobatrachus species, but the position of African Hoplobatrachus occipitalis was not clarified. Nucleotide divergence and phylogenetic data suggested the presence of allopatric cryptic species allied to Euphlyctis hexadactylus in Sundarban, Bangladesh and several parapatric cryptic species in the Western Ghats, India. The presence of at least two allopatric cryptic species among diverged Euphlyctis cyanophlyctis in Bangladesh, India, and Sri Lanka was also suggested. In some cases, our estimated divergence times matched the paleogeological events of South and Southeast Asian regions that may have led to the divergence of Hoplobatrachus and Euphlyctis taxa. Especially, land formation at Bangladesh (15–10 Ma) may have allowed the spread of these frog taxa to Southeast Asian areas, and the aridification of central India (5.1–1.6 Ma) might have affected the gene flow of widely distributed species. The present study revealed prior underestimation of the richness of the amphibian fauna in this region, indicating the possible occurrence of many cryptic species among these groups.

A functional analysis of how frogs jump out of water

Euphlyctis cyanophlyctis and E. hexadactylus are two common frog species from south-east Asia. Both species have the remarkable ability to leap from a floating position out of the water. Rana esculenta is a European species from the same family that barely manages to do so. The species' morphology, however, looks roughly the same. We studied the unique abilities of the Euphlyctis species by videotaping the three species mentioned above whilst they jumped out of the water. These recordings enabled us to study the hind leg movements and to test several hypotheses. Dif- ferences between the species only became apparent when details of the behaviour were analysed. The three species mainly differed in their slip factor at the start of the propulsive phase, resulting in a difference in slip distance. This difference could be traced back to the difference in web shape by means of a physical model. The Euphlyctis species can prevent their feet from slipping because of their rounded and convex webbing, resulting in a larger take-off veloc- ity and thereby a successful emergence out of the water. © 2004 The Linnean Society of London, Biological Journal of the Linnean Society , 2004, 83 , 413-420. ADDITIONAL KEYWORDS: Anura - locomotion - movement analysis - physical model.

Effect of lambda cyhalothrin (pyrethroid) and monocrotophos (organophosphate) on cholinesterase activity in liver, kidney and brain ofRana cyanophlyctis

The present studies investigate the induced effects of two pesticides lambda cyhalothrin (pyrethroid) and monocrotophos (organophosphate) on Rana cyanophlyctis (common skittering frog). Two different concentrations i.e. 0.1 and 1% were used and cholinesterase activity was observed in liver, kidney and brain of these frogs. It was decreased upto 34.6 and 46.3% in liver, 25.08 and 57.1% in kidney and 31.64 and 50.7% in brain under the effect of lambda cyhalothrin. In the case of monocrotophos treatment, cholinesterase decreased upto 37.7 and 57.7% in liver, 57.5 and 67.5% in kidney and 47.6 and 65.9% in brain, respectively.

Red light accelerates and melatonin retards metamorphosis of frog tadpoles

BackgroundEarlier studies from this laboratory reported that light and its spectra influence reproduction in the Indian skipper frog Rana cyanophlyctis through both ocular and extra ocular photoreception. During the course of our ongoing studies on chromotactic behaviour of the tadpoles, we noticed that tadpoles held in red light metamorphosed earlier than those held in white or other colours of light. The focus of the present study therefore was to examine the effect of red light on metamorphosis of the tadpoles.ResultsTadpoles, both intact and blind (optectomised), held in red light metamorphosed earlier than those held in white light. Addition of melatonin to aquarium water (5 micrograms/litre) prevented the red light-induced acceleration of metamorphosis both in intact and blinded tadpoles.ConclusionBoth ocular and extra-ocular perception of light is involved in red light-induced precocious metamorphosis. Melatonin inhibits the red light-induced acceleration of metamorphosis. The mechanism by which red light accelerates metamorphosis is not yet known. Melatonin counteracts red-light induced acceleration of metamorphosis in this tadpole.

Annual Growth Layers in the Phalanges of the Indian Skipper Frog Rana cyanophlyctis (Schn)

We studied the periodicity of formation of growth marks in the bones of the tropical frog Rana cyanophlyctis. Frogs were maintained in the laboratory for one year under natural temperature and day length. Toe clippings were made at the beginning and at the termination of the experiment. Skeletochronological comparison of initially clipped toes with those clipped at the termination of the experiment revealed that in all the frogs an additional growth mark or line of arrested growth (LAG) appeared in the phalangeal histology, suggesting that the formation of growth marks is annual in this tropical frog.

A report on the Puddle (Bleating) Frog Occidozyga lima (Gravenhorst) from theTeknaf Peninsula, Bangladesh, with notes on the presence of other vertebrates

On the basis of a six-day survey of southeastern Bangladesh Occidozyga lima appeared to be a common species in the Teknaf Peninsula. The most common amphibians of the region are the Cricket Frog Limnonectes limnocharis, Skipping Frog Euphlyctis cyanophlyctis, Ornate Narrow-mouthed Frog Microhyla ornata, Indian Bull Frog Hoplobatrachus tigerinus and Common Toad Bufo melanostictus. Two species of tree frogs Polypedates leucomystax and Polypedates maculatus are also common.

Qualitative analysis of food spectrum of five species of anuran tadpoles from Arunachal Pradesh, India

514 Received 29 December 2000 Accepted 17 March 2001 Abstract Anuran tadpoles were collected from amphibian habitats of Arunachal Pradesh during the breeding season from March to September. Taxonomic identification of the tadpoles was done with the help of existing literature (Sahu, 1981). Gut content analysis of five species of tadpoles was done to know the food consumed. Tadpoles between stage 30 to 38 (Gosner, 1960) were selected for the study. Bufo melanostictus, Amolops afghanus, Euphlyctis cyanophlyctis, Rana danieli and Rhacophorus maximus were studied. This is the first study on food habit of tadpoles in Arunachal Pradesh and will help in the study of habitat deterioration and floristic composition of amphibian habitats in future.

Microhabitat Choice of Tadpoles of Seven Anuran Species.

The habitat choice of tadpoles of seven anuran species with respect to light and dark phases was studied using a choice tank with a simulated pond edge. In each trial, which lasted for 12 hrs, twenty freshly collected tadpoles (Gosner stage 32-38) of a given species were used. After introducing tadpoles into the choice tank, their number at the surface, up the water column, and on the substrate was recorded at half-hour intervals. Four trials each for day and night were conducted for each species. Tadpoles of Rana curtipes, Rana cyanophlyctis, and Rana temporalis, which possess a ventral mouth, predominantly occupied the substrate zone, whereas those of Bufo melanostictus, Polypedates maculatus, and Rana tigrina, which have an antero-ventral mouth, utilized both substrate and column zones but with a clear preference for the substrate zone. Within the substrate zone, the number of tadpoles of B. melanostictus, P. maculatus, R. temporalis, and R. tigrina was greater at night than in the daytime, whereas the opposite was true for R. curtipes. Of these five species response for day-night changes was prominent in P. maculatus. It is unclear whether variation in the number of tadpoles with respect to day and night is due to changes in the light intensity or temperature or oxygen levels. The tadpoles of R. cyanophlyctis did not show any response to day-night changes. On the other hand, the tadpoles of Microhyla ornata, which possess an antero-dorsally placed and highly simplified mouth (devoid of teeth) preferred the surface (64%) and column (28%) zones in both light and dark phases. The tadpoles of M. ornata are not easily spotted despite their surface occupancy due to their transparent appearance. The present study shows the existence of diversity in the microhabitat choice of the anuran tadpoles that correlates well with their morphological characteristics.

Melatonin Counteracts the Stimulatory Effects of Blinding or Exposure to Red Light on Reproduction in the Skipper Frog Rana cyanophlyctis

An earlier study reported that blinding or exposure to red light stimulates reproduction in R. cyanophlyctis. The present study investigates whether melatonin counteracted blinding- or red-light-induced ovarian stimulation. The study consisted of two experiments carried out during the prebreeding (March/April) and breeding phase (August/September) of the reproductive cycle of this species. In experiment 1, exposure to red light for 30 days increased (P<0.01) the gonadosomatic index (GSI) and oviductal weights, whereas exposure to continuous darkness for the same duration decreased (P<0.01) the GSI. Data on follicular kinetics revealed an increase in vitellogenic oocytes and decrease in previtellogenic oocyte numbers following exposure to red lights. Exposure to continuous dark on the other hand increased previtellogenic oocyte and decreased vitellogenic oocyte numbers. In experiment 2, the GSI and the number of vitellogenic oocytes increased in blinded and red-light-exposed frogs. However, treatment with melatonin (15 μg sc) for 30 days to both these groups of frogs reduced the GSI, oviductal weights, and the number of vitellogenic oocytes. The results both confirm earlier finding that blinding and exposure to red light stimulate ovarian growth and also demonstrate that melatonin counteracts blinding or red-light-induced stimulation of ovarian activity. This apart, the findings from experiment 1 demonstrate for the first time that exposure to continuous dark inhibits ovarian growth in this species. Ocular melatonin seems to play an important role in regulation of reproduction in this species.

Phalangeal growth marks related to testis development in the frog Rana cyanophlyctis

AbstractA study of phalangeal skeletochronology was performed to estimate the age of male frogs, Rana cyanophlyctis. Changes in testicular morphometry, kinetics of spermatogenesis and abdominal fat body mass were studied in relation to the number of growth marks in these frogs. Demineralized, stained cross- sections of distal phalanx of the 4th toe of male frogs showed growth rings that alternated with highly chromophilic lines of arrested growth (LAGs). One to five growth rings were observed in frogs with different body size; body mass (r = 0.44) and size (r = 0.47) showed poor correlation with the number of growth rings. Testicular morphometry, number of spermatogenic cysts per seminiferous tubule cross-section, and germ cells per cyst increased with the increase in the number of growth rings. Leydig cells were few in the frogs with a single growth ring and increased in second and third year but Sertoli cell number and nuclear diameter did not change drastically.

Annual oviduct cycle in the Indian skipper frog,Rana cyanophlyctis(Schneider 1799): a morphological study

Seasonal changes in the weight, diameter, length and histological details of the oviduct were studied in adult Rana cyanophlyctis during the annual reproductive cycle. There are a pair of oviducts in this frog and each one was externally divisible into three segments, i.e., pars recta, pars convoluta and pars uterus. Histologically, the oviduct was composed of outer serosa/peritonial epithelium, middle connective tissue layer (which was very much reduced in thickness) and inner luminal epithelial lining. In the pars recta region, the inner epithelial cells formed longitudinal folds while, in the pars convoluta and pars uterus segments, the epithelial cells differentiated into gland cells and ciliated cells. There was a seasonal variation in the weight, length, diameter of different segments of the oviduct and in the height of the inner epithelial cell lining during the annual cycle. All these parameters were minimum in January (late post-breeding regression phase of reproductive cycle), increased up to Se...

Role of Temperature and Photoperiod in the Onset of Sexual Maturity in Female Frogs, Rana cyanophlyctis

Role of Temperature and Photoperiod in the Onset of Sexual Maturity in Female Frogs, Rana cyanophlyctis

Effect of exposure to continuous light and melatonin on ovarian follicular kinetics in the skipper frog, Rana cyanophlyctis.

Ovarian follicular kinetics and gravimetric changes in the ovary and oviducts were studied in the skipper frog, Rana cyanophlyctis, following exposure to continuous light and melatonin treatment during the breeding season. Daily late-afternoon injections of melatonin (15 micrograms subcutaneous) for 30 days decreased the gonadosomatic index (GSI), whereas continuously available melatonin from subcutaneous implants did not influence the GSI compared to those of controls. Exposure to continuous light for 30 days stimulated the GSI, and melatonin given as daily injections prevented the continuous-light induced increase in GSI. Oviductal weights decreased only in the melatonin-injected groups. Data on follicular kinetics revealed a decrease in first-growth-phase (FGP) oocytes and an increase in medium-sized second-growth-phase (MSGP) and large-sized second-growth-phase (LSGP) oocytes following continuous-light exposure. Melatonin administered to continuous-light-exposed frogs did not change the FGP oocyte number; however, it reduced both the MSGP and LSGP oocytes. Melatonin administration to frogs held in a light and dark cycle increased FGP oocytes and decreased MSGP and LSGP oocytes. Atretic follicles increased in all melatonin-treated groups. The results suggest that continuous light stimulates and melatonin inhibits reproductive function in this species.

Ovarian Follicular Kinetics in Response to Enucleation and Parietal Shielding inRana cyanophlyctis

Ovarian follicular kinetics, gravimetric changes in the ovary and the oviduct, were studied in the skipper frog,Rana cyanophlyctis,following enucleation (ENX) and parietal shielding (PS), during the breeding reason. PS was to prevent extraoptic photoreception by the pineal via the frontal organ. The gonadosomatic index (GSI) was high in ENX and PS frogs (P<0.01). The highest GSI occurred in frogs that were both ENX and PS (P<0.01). Percentage of oviductal weight decreased (P<0.01) in PS frogs and increased (P<0.01) in those subjected to both ENX and PS. Oviductal weight of ENX frogs was unchanged. Data on follicular kinetics revealed a decrease (P<0.01) in the ENX group in the number of first growth phase (FGP) oocytes and atretic follicles (AF), whereas the number of medium-sized secondary growth phase (MSGP) oocytes and large-sized secondary growth phase (LSGP) oocytes increased (P<0.01). There was a similar pattern of follicular kinetics in ENX+PS frogs. However, following PS, the number of FGP oocytes and AF increased (P<0.01) and decreased (P<0.01) in the MSGP and LSGP oocytes. The lower oviductal weight in PS frogs correlated with reduced SGP oocytes, the major source of estrogen. The importance of lateral eyes and the frontal organs in the transduction of environmental signals to the neuroendocrine–reproductive axis is indicated in this species. That recruitment of FGP to SGP is inhibited only in the PS group suggests that the frontal organ plays an important role in ovarian follicular kinetics.

Age related changes in ovarian follicular kinetics in the Indian skipper frogRana cyanophlyctis (Schn.)

Changes in ovarian follicular kinetics were studied in relation to aging in the Indian skipper frog Ran a cya noph ly cti s. Age was determined by skeletochronology, by counting the number of growth rings and lines of arrest of growth from the cross sections of 4th phalange of 4th toe. For follicular kinetics study oocytes were counted under binocular using 10% of Bouin's fixed ovary and they were classified into first growth phase, medium-sized second growth phase, large-sized second growth phase and atretic follicles. Analysis of phalangeal cross sections indicated that frogs ranging 14-54 g in body weight and 4·9-8·9 cm in body size showed 1-7 year rings. Frogs that weighed 14-16 g showed 1 year ring, and contained immature ovaries; those with 18 g body weight had one to two year rings, in which second growth phase oocytes appeared for the first time in the primiparous ovary. Frogs with 20-54 g body weight showed 2-5 year rings in which ovary contained 5-24% of second growth phase oocytes. Further, body weight, body size, ovarian weight, number and size of second growth phase oocytes and total number of oocytes showed a significant (P < 0·05) positive correlation, while, the number of first growth phase and atretic follicles showed a poor correlation with age. The results suggest that in nature, the age of Rana cyanophlyctis ranges between 1-7 years. Phalangeal growth rings are formed annually. Females attain sexual maturity in 2nd year. Frogs with 2-5 years of age may constitute breeding females. Body weight, body size, ovarian mass, number of second growth phase and total oocytes, and egg size increase with age up to 5 years.

Bioacoustic analysis of frog calls from northeast India

Mating calls of three frog species abundant in northeast IndiaRana tigerina,Rana cyanophlyctis andRana limnocharis were recorded in the fields of Assam and Meghalaya during their breeding season (July-August, 1991). The calls were analysed for their temporal and spectral characters. They were species specific, with distinct call duration and call period, number of pulses per call and interpulse interval, and dominant frequency and frequency domain. A comparison of the mating calls ofRana cyanophlyctis with those of the siblingRana ehrenbergi from Yemen showed differences in their temporal and spectral characters, supporting the suggestion that these two species are distinct species, rather than subspecies of the same species. Differences in the temporal and spectral pattern were found in the mating calls of morphologically alike specimens ofRana limnocharis, indicating that the present morphotypeRana limnocharis in northeast India is composed of several species.

Quantitative analysis of the community structure of tropical amphibian assemblages and its significance to conservation

Amphibian community structure in five tropical sites was studied using dominance, diversity, evenness indices, niche breadth and overlapping scores and association analysis. Ten species of amphibians with average density/ha varying from 8 to 49 in different sites were collected. Rana limnocharis and Bufo melanostictus were respectively the dominant amphibia in paddy fields and other sites. Niche breadth scores indicated Rana limnocharis, Bufo melanostictus and Rana cyanophlyctis as habitat generalists indicating wide tolerance to environmental gradients. Five frog species i.e. Rana tigerina, Microhyla ornata, Ramanella variegata, Uperedon systoma and Polypedates maculatus were considered habitat specialists indicating narrow tolerance to environmental gradients. Niche breadth scores were found to be a function of the cumulative relative abundance value of different species. The niches of Rana limnocharis and Rana cyanophlyctis, Bufo melanostictus and Bufo stomaticus showed maximum overlapping. Rana tigerina showed maximum niche overlapping with Rana variegata in paddy fields and with Microhyla ornata when all sites were taken together. The coefficient of community index was maximum between the paddy fields and minimum between the paddy fields and forest site. Rana tigerina occurred very sparsely and analysis of data indicates that its population are threatened and require conservation measure.

Effect of Chronic Exposure to the Mercurial Fungicide Emisan registered on Spermatogenesis in Rana cyanophlyctis

Effect of Chronic Exposure to the Mercurial Fungicide Emisan registered on Spermatogenesis in Rana cyanophlyctis

Effects of Exposure to Sublethal Mercuric Chloride on the Testis and Fat Body of the Frog Rana cyanophlyctis

Effects of Exposure to Sublethal Mercuric Chloride on the Testis and Fat Body of the Frog Rana cyanophlyctis

Effect of Sublethal Concentration of Mercuric Chloride on the Ovary of the Frog Rana cyanophlyctis

Effect of Sublethal Concentration of Mercuric Chloride on the Ovary of the Frog Rana cyanophlyctis